Laser tracker-based inspection of machine tool components

When a customer of Talleres de Guernica’s asked for a precision chuck with 7 m diameter, the Spanish machine tool company designed a manufacturing process based on permanent quality control. With the Leica Absolute Tracker AT401, new business opened up.

 

The machine tool company Talleres de Guernica, based in the city of Guernica, where the Basque Country’s heritage is omnipresent, has a long experience in metal machining since its foundation in 1916. Over the years, Talleres de Guernica constantly modernized their manufacturing technology and widened their product range. Their production became increasingly automated, parts grew, tolerance values however shrunk.

 

Today, Talleres de Guernica offer mainly chucks and jaws for many types of machines. Most parts have a diameter of 2 m maximum – pure routine for Quality Manager Manu Fuentes and his team. When a customer asked for a chuck to be used in a manufacturing centre for wind turbine components with a diameter of 7 m and a weight of 65t, new manufacturing and inspection methods had to be considered.

 

Manu Fuentes looks back: “We did not have a lot of experience with such dimensions. But we knew that manufacturing mistakes would cost us a lot of time and money. So we decided to extend our measuring instruments and build the large part based on highly accurate data. For us, the maximum acceptable deviation is 0.05 mm.”

 

While evaluating different metrology tools, the Talleres de Guernica team came to the conclusion that a laser tracker is the best solution for the measurement of a large and immobile object. “Measuring with other tools, especially with analogue ones, is impossible for us”, said Manu Fuentes. The decision was in favour of the Leica Absolute Tracker AT401. This lightweight portable CMM can perform measurements within a volume of up to 320 m. It is battery operated and certified according to the IP54 protection class, which allows operation under rough conditions. The system is set up wirelessly so that one operator with a remote control is sufficient. PowerLock technology directs the laser beam automatically towards the user. Thanks to PowerLock, new users can be trained quickly.

 

Manu Fuentes: “The portability of the system was the decisive factor for us. We can put it on the chuck and are ready to measure within a couple of moments. The measurement itself is done very fast.” Between the single manufacturing steps, the laser tracker is used to check a list of critical elements on the chuck. This list includes the position of the jaws and their features such as holes and edges or the flatness of the chuck’s surfaces. “Basically, we measure to exclude any risk during the manufacturing process”, adds Michel Clavier, Director of Production. “And this decision is confirmed every time the measurement raises a question mark. We will deliver a perfect part to our customer.”

 

The laser tracker from Leica Geosystems influenced Talleres de Guernica‘s presence on the machine tool market. They are now able to manufacture chucks in enormous sizes. Manu Fuentes sums up: “The Hexagon Metrology solution with Leica Absolute Tracker and PC-DMIS software are a strong package and exactly what we needed to solve our business challenge. Thanks to the tracker, we can access new market segments.”